Patent EA-003457-B1 (EA)
Title: Dyeable fluoropolymer fibers
Inventor: UY WILLIAM CHENG
IPC: C08L27/18
Filed: 1999-05-26
Abstract: 1. A fiber, comprising a blend, comprising: a first copolymer and a second copolymer; said first copolymer comprising monomeric units of tetrafluoroethylene and a first comonomer selected from the group consisting of a fluoroalkyl vinyl ether, a fluoroalkene having at least 3 carbons, and ethylene; said second copolymer comprising monomeric units of tetrafluoroethylene and a second comonomer comprising a fluoroalkenyl radical having attached thereto a pendant group comprising a radical represented by the formula: -(O-CF2CFR)a O-CF2CFR'Q, wherein: R and R' are independently selected from F, Cl or a perfluorinated alkyl group having 1 to 10 carbon atoms; a = 0, 1 or 2; Q is selected from the group consisting of -SO3<->Z<+> and -SO2X; Z<+> is H<+>, an alkali metal cation, or a cation derived from a compound selected from the group consisting of a cationic dye, a cationic whitener, a cationic flame retardant, a cationic antistatic agent, and mixtures thereof; and X is F or Cl; said first copolymer comprising about 0.5-20 mol-% of the first comonomer; said second copolymer comprising about 5-25 mol-% of the second comonomer; and said blend comprising about 1-10% by weight of said second copolymer. 2. The fiber of Claim 1 wherein the first comonomer is hexafluoropropylene, perfluoropropylvinylether, or perfluoroethylvinylether, and the second comonomer is represented by the formula CF2=CF-(OCF2CF-(CF3))a OCF2CF2SO3<->Z<+>, wherein a = 0 or 1. 3. The fiber of Claim 2 wherein Z<+> is the cationic dye. 4. A fiber, comprising a terpolymer, comprising: monomeric units of a first termonomer of tetrafluoroethylene; a second termonomer selected from the group consisting of a fluoroalkyl vinyl ether, a fluoroalkene having at least 3 carbons, and ethylene; and a third termonomer comprising a fluoroalkenyl radical having attached thereto a pendant group comprising a radical represented by the formula -(O-CF2CFR)a O-CF2CFR'Q, wherein: R and R<1> are independently selected from F, Cl, or a perfluorinated alkyl group having 1 to 10 carbon atoms; a = 0, 1 or 2; Q is selected from the group consisting of-. -SO3<->Z<+> and -SO2X; Z<+> is H<+>, an alkali metal cation, or a cation derived from a compound selected from the group consisting of: a cationic dye, a cationic whitener, a cationic flame retardant, a cationic antistatic agent, and mixtures thereof; and X is F or Cl; said terpolymer comprising about 0.5-5 mol-% of the second termonomer and about 0.1-2 mol-% of the third termonomer. 5. The fiber of Claim 4 wherein the second termonomer is perfluoropropylvinylether, perfluoroethylvinylether, or hexafluoropropylene, and the third termonomer is CF2=CF-(OCF2CF-(CF3))a OCF2CF2SO3<->Z<+>, wherein a = 0 or 1. 6. The fiber of Claim 5 wherein Z<+> is the cationic dye. 7. A process for producing a fiber, the process comprising the steps of: mixing a first copolymer and a second copolymer to form a mixture, said first copolymer comprising monomeric units of tetrafluoroethylene and a first comonomer selected from the group consisting of a fluoroalkyl vinyl ether, a fluoroalkene having at least 3 carbons, and ethylene; and said second copolymer comprising monomeric units of tetrafluoroethylene and a second comonomer comprising a fluoroalkenyl radical having attached thereto a pendant group comprising a radical represented by the formula -(O-CF2CFR)a O-CF2CFR'SO2X, wherein R and R' are independently selected from F, Cl or a perfluorinated alkyl group having 1 to 10 carbon atoms; a = 0, 1 or 2; and X is F or Cl; said first copolymer comprising about 0.5-20 mol-% of the first comonomer, and said second copolymer comprising about 5-25% of monomeric units of said second comonomer; heating said first and second copolymers, simultaneously with or subsequent to mixing, to a temperature sufficient to form a molten blend without significant degradation of either copolymer, said blend comprising about 1-10% by weight of said second copolymer; feeding the molten blend to a melt spinning device having a spinneret having at least one aperture, each aperture defined therein by a wall; extruding the molten blend through the at least one aperture to form a fiber. 8. The process of Claim 7 further comprising cooling the fiber and contacting the fiber with a solution comprising an alkali metal base to yield a cation-receptive fiber. 9. The process of Claim 8 further comprising contacting the cation-receptive fiber with a cationic modifying agent selected from the group consisting of: a cationic dye, a cationic whitener, a cationic flame retardant, a cationic antistatic agent, and mixtures thereof. 10. A process for producing a fiber, comprising the steps of: extruding a composition comprising a molten terpolymer through at least one aperture of a spinneret of a melt spinning device to form a fiber, each aperture defined by a wall within said spinneret, said terpolymer comprising monomeric units of a first termonomer of tetrafluoroethylene; a second termonomer selected from the group consisting of a fluoroalkyl vinyl ether, a fluoroalkene having at least 3 carbons, and ethylene; and a third termonomer comprising a fluoroalkenyl radical having attached thereto a pendant group comprising a radical represented by the formula -(O-CF2CFR)a O-CF2CFR'SO2X, wherein R and R' are independently selected from F, Cl or a perfluorinated alkyl group having 1 to 10 carbon atoms, a = 0, 1 or 2, and X is F or Cl; said terpolymer comprising about 0.5-5 mol-% of the second termonomer and about 0.1-2 mol% of the third termonomer. 11. The process of Claim 10 further comprising cooling the fiber and contacting the fiber with a solution comprising an alkali metal base to yield a ration-receptive fiber. 12. The process of Claim 11 further comprising contacting the cation-receptive fiber with a cationic modifying agent selected from the group consisting of: a cationic dye, a cationic whitener, a cationic flame retardant, a cationic antistatic agent, and mixtures thereof. 13. The process of Claims 7 or 10 wherein there are a plurality of apertures and the walls defining the apertures are separately heated from the rest of the melt spinning device to a temperature in the range of about 400 to about 500 degree C. 14. The process of Claim 9 or 12 wherein prior to contact with the cationic dye the cation-receptive fiber is blended with a second dyeable fiber.